Brake Judder

[A2Z]

Hi All,

I'm getting a fair bit of judder through the steering column under braking (anything over "fairly" hard). I thought it was the front discs, but upon having a look, whilst they are not new items, they are still pretty good. The pads are of a no particular brand and have life left in them. They did a track day at Anglesey over the summer without complaint.

It only started recently and I thought it was because the car had been stood on the drive for a couple of weeks. A good drive out didn't improve them.

Fluid is new and bled through
Front tyres are new and balanced
Geo is spot on
Calipers not binding (wheels didn't get hot after a good run out)

Was going to change the pads and discs for peace of mind. Should I be looking for anything else?

[MX-5 Lazza]

Could be a warped disc. I have this at the moment but I'll leave replacement until after my next track day as it doesn't bother me much and the discs are otherwise in pretty good nick.

[V6]

Twisted brake hose? This was causing juddering in my Alfa recently.

[snotrag]

Have you got ABS? I havent on mine so I've no idea how quick it is to kick in on the MX5. Could be a bit over sensitive due to a faulty sensor - otherwise, std thing would warped discs.

As Lazza said, annoying more than anything else as long as its not too major.

[A2Z]

No ABS but I tend to agree with you all regarding the warped discs. Thanks everyone.

[OllieWinchester]

You won't be able to see if a disc is warped by eye. I reckon its that.

[Firefox1]

A few years ago my late father in law had a similar problem with a Ford Granada which like the MX5 has ventilated discs on the front, after checking I found that the disc was cracked through the ventilation slots which you cannot see with out taking the wheel off.

The simple way to check the disc runout is to hold a pencil or piece of chalk firmly against the edge of the caliper about the thickness of a piece of paper away from the disc, have some one turn the disc very slowly you should find if the disc is out of true then then the high spot will be indicated.You may need to check both disc faces.

The disc maximum run out is 0.05mm or 0.002in or about the thickness of a sheet of writing paper but to check to that accuracy you need a magnetic base and dial test indicator.